Operating Leases - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2020 ft²
Lessee, Lease, Description [Line Items]
Office space	50,800
Corporate Office Space and Manufacturing Facility
Lessee, Lease, Description [Line Items]
Lease expiration date	Dec. 31, 2022
Office Space And Manufacturing Facility
Lessee, Lease, Description [Line Items]
Operating lease option to extend renewal term description	five-year term
Office Space Zaventem Belgium
Lessee, Lease, Description [Line Items]
Office space	3,900
Lease expiration date	Dec. 31, 2021
Operating lease option to extend renewal term description	three-year term